Filter and method of making



Nov. 6, 1928.

F. E. DENNISON ET AL FIL'I' EIR AND METHOD OF MAKING Filed Jan. 29, 1926 f 701/6703 7'5 Damn/0 71.,

i311. ward W I The recess e u Need-19128.

UNITED" STATES PATENT OFFICE.

' IBEN'CH E. DEKNISON S. IRELAND, OI IBELOIT, WISCONSIN, ASSIGNQBS '10 NATIONAL REFRIGERATION CORPORATION, 01 BELOIT, WISCONSIN, A CORP OBL- TION OI DELAWARE.

rrmnn AND imzrrron or Jaime.

:Appliization filed January 29, 1926. Serial 150. 84,574'.

This invention pertains generall to filters and specifically to filters of the c aracter adapted for use in a mechanical refrigeration system for the pur ose of preventin 'dirt, I sediment, scale, an solid particles vari- 'ous kinds from obtaining accessto the expansionvalve oncompressor. Our invention may, however, be utilized for many other analogous purposes. r

One ofthe objects of our invention is to a filter which will effectually screen provide from fluid flowing thereout solid particles through, and which Will present a maximunr so that the liabilarea of screening surface,

stopped up ity of its becomin gclogged oris reduced to a minimum.

Another obiect of the invention is'to provide a filter which will not beliable to leak, but which will bestrongand substantial-in construction and durable in operation.

A further object is the provision of a novel and a practical method for the manufacture of our novel. filter. g

Iii-order to facilitate an understanding of our invention, we have shown on the accompanying drawings a preferred embodiment thereof, from which, when considered in connection with the following description, the invention and manyiof itsinherent ad vantafges should be, readily appreciated.

Re erring to the drawings: 4

Fig. 1 is a perspective view of a filter embodying our invention,

Fig. 2 is a vertical sectional view illustrat- I ing one step in the manufacture of our filter,

ig. 3 is a similar fragmentary view showin another step in the manufacture, and Tig. .4 is a sectional view on theline.4-4'

of Fi 2.

Re er'rin to the'drawings more in detail, reference c aracter 5 indicates generally a table bench or frame utilized in the manu facture of our improved filter and upon which is secured by bolts 6, or'otherwise, the

base 7 of a'mold consistingof a disc or plate 8 provided with an annular recess 9 and supported .upon a hollow neck or'standard 11-.

9 forms the" mold proper into which the molten metal forming the ends of 'ourimproved filter is poured. y In order to prevent the metal from chillin ening when poured into the mol a burner 12 is located immediately beneath the same soas to maintain the requisite temperature thereof. r

"With the mold is adapted to cooperate a ;form generally indicated by reference character 13, comprising a hollow body portion 14 provided with a hollow extension 15' at one end and a radial flange 16 at its opposite end. equipped with two depending annular flanges 17 and 18 respectively. ThlS, form when removed from the mold is adapted to receive the screen elements embodied in the structure of our improved filter.

Whilean'y preferred numberof screen elements may be employed, I have shown for purposes of illustration, three of such elements, the inner one beingindicated by reference character 21, and the outer one by 22. These screen elements are made of fine wire woven into a mesh fabric and preferably the fabrics are of-increasing fineness of mesh from theoutside to the interior of'the filter, that 'is the outer screen 22 has the coarsestmesh,

19, the intermediate one by the inner screen 19, the finest, and the screen 21, an intermediate mesh. These screensare cut to the proper length and the endsof each are joined b a double seam, so as to. form a solderless ]oin t. It will be observed from Fig. l that the screen joints indicated by reference characters 23, 24 and 25 res ective'l are so distributed inthe assemble filter t at they offer minimum resistance to the flow of fluids through the filter.

The form 13 havin the meld, the screen efiements. are assembled thereonas shown inFi s. 2 and 3. Element 19 slips over and loose y embraces the body portion 14 of the form. Element 21 is braced at its upper end by the flange 17, and

element 22J'is similarly embraced at its upper,

end by the flange 18. The mold recess Sis now filled with the molten metal, whereof the mold, cold water is now introduce into the form or hard through a cold water pipe 26 extending downwardly into the extension This water will cool the form and been removed from is positioned as" shown in Fig. of all of the the surroundin mold," thus hastening the hardening of t e metal. The water overflows from the form and is discharged through an overflow pipe 27.

When the mold has been sufficiently cooled, the form is lifted and the metal ring or filter end 28 is ejected from the mold in the following manner: A rack bar 29, extending downwardly through the frame adapted to be actuated by a pinion 31 which may be operated by a crank, is moved upwardly against the lower end of the projection 15 to thereby elevate the form. A cross-head 32, carried by the rack bar is provided with a pluralit of ejector pins 33, the upper ends of w ich normally lie flush withthe bottom of the mold recess 9. Upward movement of the rack bar and cross head moves the ejector pins upwardly to eject the cast ring 28 from the mold. When the ring has been freed from the mold, the screens may be withdrawn from the form and placed on another form 34, shown in Fig. 3. The mold recess 9 is again filled with molten metal, ,whereupon the form 34 is lowered to introduce the lower ends of the screened members into the metal as shown in Fig. 3. Cold water is then introduced again through the pipe 26 to'coolthe metal, whereupon it is ejected, thus completing the filter which consists of the three screen elements previously mentioned, the top ring 28 and the bottom rin 35.

It will be 0 served that the ends of the screen elements are firmly embedded and cast into the top and bottom rings 28 and 35, so that the spaces between the screen elements are effectually sealed and any leakage around the ends of the elements is recluded. The filter comprising the t ree screens with the integral top and bottom rings, forms a complete unit which may be assembled in an expansion valve or any other apparatus, so that the fluid to be filtered must pass throu h the successive screens of the filter from t e outside toward the inside. If the filter is clamped in position in a chamber to which the unfiltered fluid is delivered, the fluid, after passing through the screens willibe discharged from a point centrally of the filter.

' The details of construction of the filter and the various steps utilized in its manufacture may obviously be variedwithin considerable'limits without departing from the spirit of the invention as set forth in the following claims.

We claim:

1. A filter comprising a plurality of cylindrical screen elements arranged in spaced relation and of a decreasingly finer mesh from the outside to the inside, and a member fused to one end of the elements for sealing the spaces between them atsaid end and uniting the said elements. p

2. A- filter comprisin a plurality of concentricallg arranged cylindrical screens, and end mem ers cast upon the end margins of said screens, uniting the same into a unitary structure and closing the ends of the spaces between the screens.

3. A filter comprising a pluralit of concentrically arranged screens of di erent diameters having their ends connected by metal cast upon the end margins of the screen.

4;. A filter comprising a plurality of concentrically arranged cylindrical screens of decreasingly finer mesh from the outside toward the inside, and cast metal end rings into which the end margins of said screens project and to which they are secured by the solidifying of the rings whereby a unitary structure is produced.

5. .A filter comprising a plurality of screen elements arranged in juxtaposed spaced relation and a member fused to one end of the elements for sealing the spaces between them at said end and uniting the said elements.

6. A filter comprising a plurality of screen elements arranged in juxtaposed spaced relation and a member moulded to one end of the elements for sealing the spaces between them at said end and uniting the said elements.

FRENCH E. DENNISON. WARD S. IRELAND. 

